Grinding machine



June 2 6, 1945. R. H. CRAMER 2,379,231

GRINDING MAcHiNE Filed 001;. 22, 1942 2 Sheets-Sheet 1 /NVN 7 0/2 AMYMOND H. C/QAMBQ,

/'//5 ATTOR/VE).

June 26, 1945. CRAMER 2,379,281

GRINDING MACHINE Filed Oct. 22, 1942 2 Sheets-Sheet 2 l/vve'wroe: lAYMo/vo HC/QAMFIQ,

HIS A TTO/QNE).

Patented June 26, 1945 GRINDING MACHINE Raymond H. Cramer, Bloomfield, N. 1., assiguor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application October 22, 1942, Serial No. 462,929

15 Claims.

This invention relates to grinding machines and comprises all of the features of novelty herein disclosed. An object of the invention is to provide improved means for holding a plurality of work pieces against their support, especially for holding a plurality of rings to be ground internally as a group on a chuckless grinding machine. Another object is to provide individual pressure members for each piece in a series together with means to apply different pressures to selected pieces as desired.

To these ends and also to improve generally upon apparatus of this character, the invention consists in the various matters hereinafter de scribed and claimed. In its broader aspects, the invention is not necessarily limited to the sp cific constructions selected for illustrative purposes in the accompanying drawings in which Fig. 1 is an end elevation of the machine with some parts in section;

Fig. 2 is a view similar to Fig. 1 with certain movable parts in a different position;

Fig. 3 is a perspective view of a shoe carrier or arm;

Fig. 4 is a plan view of the machine; and

Fig. 5 is a sectional view of a series of shoes engaging a different kind of work.

This machine is designated especially for the internal grinding of a plurality of hollow work pieces W at one setting, the work pieces being coaxially supported in side by side contact and rotated by a plurality of rolls while a grinding wheel G is reciprocated along the inner wall of the work in opposition to one of the rolls and toward which roll the grinding wheel is fed. In order that the pressure of the various work pieces against the supporting rolls may be varied as desired, an individually yieldable and adjustable pressing member or shoe presses against each work piece.

A driven backing roll ill is mounted on a driven shaft journalled for rotation in a head I2 which is secured by screws I 4 to a slide IS, the latter being adjustable horizontally on a base l8. A lug 25) projects rearwardly from the head and supports a shaft 22 on which is rockably mounted a spring pressed arm 24 having a wiper 25 engaging the roll to. The work engages the periphery of the roll it and the periphery of a supporting idler roll 30 which has a shoulder 32 to engage one end of one work piece while an adjustable flange 34 engages the end of another work piece. The supporting roll 30 is mounted for rotation on a slide 36 which is adjustable along an incline by means of a screw 38, this adjustment being for the purpose of supporting work pieces of any selected diameter at the same level. The grinding wheel G is preferably fed in a horizontal plane in which lie the centers of the work pieces and the center of the roll l0.

Projecting upwardly from the head I2 are a pair of lugs 40 supporting a. rock shaft 42 which overhangs the driving r011 l0. Secured by a key 44 against rotation on the overhanging portion of the shaft is a plurality of blocks 46 which are split and clamped to the shaft in axially adjusted position by clamping screws 48. The upper surface of each block 46 has a little upwardly projecting tongue 50 entering a groove 52 on the lower surface of a long arm 54, the arm having a long slot 56 for clamping screws 58 which secure it in adjusted positions lengthwise to the block 45. There are as many of these arms and blocks as there are work pieces and each arm constitutes a carrier for a yieldable shoe or pressing member which holds its work piece against the rolls I 0 and 30. At the front of each arm is a housing 60 containing a coiled spring 62 which engages an abutment washer 64 on a shouldered stud 66 which is threaded in the housing to adjust the tension of the coiled spring. A look nut 61 maintains the adjustment. The spring is piloted at its lower end over a stud 68 secured to the forward end of an auxiliary arm 10 oocupying a recess in the long arm 54 and being pivoted at 12 thereto. The front of each arm 10 has a notch receiving a, locating tongue 14 on an insert 16 which is fastened in place by a clamping screw 18. The lower end of the insert is tipped at with hard metal such as tungsten carbide to provide a hard wearing sur-- face or shoe to engage the work piece W. Each work engaging surface acts as a pressure shoe to hold the workpiece against the driving roll and the supporting idler roll and the pressure on each piece can be controlled by the adjustment of its spring.

At the opposite end of the rock shaft 42 from its overhanging end is clamped a lifter arm 82, the latter being split and secured to the rock shaft by clamping screws 84. A collar is pinned on the shaft on the opposite side of the lug 40 from the arm 82 to co-operate therewith in preventing endwise movement of the rock shaft. The front of the lifter arm has a vertical opening 86 loosely admitting a long anchoring screw 88, the screw having an enlarged portion provided with flats 90 so that it can be turned for vertical adjustment, the lower end of the screw being threaded in any suitable part. En-

circling the anchor screw ii is a coiled spring I which bears against an adjusting nut is threaded on the screw, the spring also bearing against an equalizing washer 90 whose upper surface is crowned to rockably engage the lower surface of the lifter arm 82. At the upper end of the opening I. are slanting walls 91 forming a seat for cylindrically crowned surfaces of a generally rectangular centralizing plate Ill loosely surrounding the screw 88 and whose upper surface is flat and adapted to be engaged by a cam surface I02 on a bifurcated cam member Ill. The cam member straddles the threaded anchoring screw '8 and its opposite cheeks have bearing openings to pivot on a short pivot shaft I" which is tapped to receive the anchoring screw as, the shaft being secured in adjusted position in the anchoring screw by a set screw Ill. The cam member I" can be rocked by a handle Hi from the position indicated in Fig. 1 where a flat surface en gages the centralizing plate I" to a work releasing position indicated in Fig. 2 in which a second flattened surface III at the end of the cam surface I02 engages the centralizing plate.

In the Fig. 1 position, the cam forces down the lifter arm '2 and compresses the spring 94, this action rocking the shaft 42 and causing all of the pressure shoes to come down and engage the work pieces and compressing each of the springs 62 more or less depending on their individual adjustment. If the work pieces vary a little in external diameter the coiled springs 62 will compensate for it. By adjusting the springs 62, a greater pressure can be placed upon any of the selected work pieces as desired. For instance, it is sometimes desirable 'to have a greater pressure exerted on the two endmost pieces of a large group as they have more tendency to axial displacement than the middle pieces. The corresponding springs 82 are then given a larger initial compression. The swinging of each auxiliary arm II is limited by its rear end coming into contact with the long arm or carrier 54. Upon swinging the handle III to the Fig. 2 position, the coil spring I expands upwardly, raising the lifter arm 02 and all the long arms or carriers 54 to withdraw all the pressure shoes from the work pieces.

Figure 4 indicates two wide work pieces in axial alignment and two pressure shoes. Figure 5 indicates six comparatively narrow work pieces, herein shown as the inner race rings R of roller bearings such races having outwardly projecting flanges F which engage the driving roll Is, the supporting roll 30 and the shoes Ill. The shoes bearing on the outermost work pieces are indicated as exerting greater pressure because their springs 62 are compressed by inward adjustment of the studs 66.

I claim:

1. In a machine of the character indicated, means for supporting and rotating a series of work pieces in side by side relation for a machining operation, work pressing members individually engaging the work pieces, means for causing some of the members to exert. greater pressure than the others on their respective work pieces, and mechanism for moving all of said pressing members as a unit towards or from the work.

2. In a machine of the character indicated, means forsupporting and rotating a series of round work pieces in side by side relation for a machining operation, more than two work pressing members individually and resiliently engaging the work pieces, and means for causing the resilient pressure on the outside pieces in the series to be greater than on the pieces in between.

3. In a machine of the character indicated. means for supporting and rotating a series of round work pieces in side by side relation for a machining operation, work pressing members individually engaging the work pieces, a series of carriers one for each member, a spring reacting between each member and its carrier, and means for changing the spring pressure of any selected members.

4. In a machine of the character indicated, means for supporting and rotating a plurality of round work pieces in side by side relation for a machining operation, a plurality of work pressing members one to engage each work piece, a movable carrier for each member, a spring reacting between each member and its carrier, and means for actuating the carriers in unison to carry the members into or out of resilient engagement with their work pieces.

5. In a machine of the character indicated, means for supporting and rotating a plurality of round work pieces in side by side relation for a machining operation, a plurality of work pressing members one to engage each member, a movable carrier for each member, a spring reacting between each member and its carrier, means for limiting relative movement between each member and its carrier, and means for actuating the carriers in unison to carry the members into or out of resilient engagement with their work pieces.

6. In a machine of the character indicated. means for supporting and rotating a plurality of round work pieces in side by side relation for a machining operation, a plurality of work pressing members one to engage each work piece, a swinging carrier for each work pressing member, each carrier having means for yieldably supporting one of the members thereon, and a rock shaft for swinging all of said carriers in unison.

7. In a machine of the character indicated, means for supporting and rotating a plurality of round work pieces in side by side relation, a plurality of rockable carriers one for each work piece, means for rocking the carriers as a unit towards or from the work pieces, and a work pressing member movably supported by each carrier, each member being individually yieldable with respect to its carrier as it is brought against its work piece.

8. In a machine of the character indicated, spaced rolls for supporting and rotating round work, a yieldable work pressing member for urging the work against the rolls, a carrier for actuating the member towards or from the work, a spring between the carrier and the work pressing member, a spring urging the carrier and the member away from the work, and a cam for actuating the carrier in opposition to the spring to bring the work pressing member into resilient engagement with the work.

9. In a machine of the character indicated, spaced rolls for supporting and rotating round work, a work pressing member for holding-the work against the rolls, a rock shaft for actuating the member and having an actuating arm, a spring reacting on the arm in one direction, an anchoring member having a pivot shaft, and a cam mounted on the pivot shaft to actuate the arm in opposition to the spring.

reacting on the arm, a pivot shaft, and a cam pivoted on the shaft to actuate the arm in 0pposition to the spring.

11. In a machine of the character indicated, resilient work engaging means having an actuating shaft, an arm on the shaft, a spring reacting on the arm, a pivot haft, a cam pivoted on the shaft, and a centralizing plate interposed between the cam and the arm.

12. In a machine of the character indicated, resilient work engaging means having an actuating shaft, an arm on the shaft, an anchoring member extending through the arm, a spring reacting on the arm, a pivot shaft on the anchoring member and a cam mounted on the pivot shaft to actuate the arm in opposition to the spring.

13. In a machine of the character indicated, spaced'rolls for supporting and rotating round work, a rock shaft, 9. carrier fixed to the shaft, an arm pivoted to the carrier and having a work engaging member, and a spring interposed between the arm and its carrier.

1 4. In a machine of the character indicated, spaced rolls for supporting and rotating round work, a rock shaft, a carrier fixed to the shaft, an arm pivoted to the carrier for limited pivotal movement, a spring urging the arm towards its limited position, and a work engaging shoe carried by the arm.

15. In a machine of the character indicated. means for supporting and rotating a series of work pieces in side by side relation for a. machi ing operation, a corresponding series of at least three work pressing members individually pressing against their" respective work pieces, and means for causing the two outermost pressing members in the series to exert a greater pressure on their respective pieces than any pressing member in between exerts upon its respective piece.

RAYMOND H. CRAMER. 

